Swing grinder suspension



Feb. 17, 1959 R. OLSEN swmc GRINDER SUSPENSION Filed Sept. 10, 1957I/VVENTOI? RIC/M R0 OLSEN 1- w Attorney United States Patent 1 2,873,558SWING GRINDER SUSPENSION Richard Olsen, Chicago, llh, assignor to UnitedStates Steel Corporation, a corporation of New Jersey ApplicationSeptember 10, 1957, Serial No. 683,099

- 1 Claim. (Cl. 51-99) The present invention relates generally to swinggrinders and more particularly to an improved suspension means forsupporting a swing grinder.

The conventional swing grinder consists of a longitudinal frame having adriving motor mounted adjacent one end and a grinding wheel journaled onthe other end. The motor and grinding wheel assemblies are equipped withpulleys whereby the grinding wheel is rotated by V-belts running fromone pulley to another. The grinder is suspended from a chain fall bymeans of a bracket located at approximately the center of gravity of theframe so that the grinder is in balance when suspended. In operation,the operator pivots the grinding wheel end of the assembly downwardlyand forces the grinding wheel against a surface to be ground by exertingpressure on a handle bar provided on the frame adjacent the grindingwheel.

The grinding pressure that can thus be exerted by an operator is limitedand this constitutes a serious disadvantage in the use of swinggrinders. Experience has shown that an average workman can exertapproximately 100 pounds per square inch grinding pressure with aconventional swing grinder. This is a limiting influence on the amountof work that can be produced by an operator in a given period.

It is accordingly, an object of the invention to provide an improvedsuspension for a swing grinder whereby the grinding pressure that can beexerted is substantially increased over that possible heretofore.

It is another object of the invention to provide an improved suspensionfor a swing grinder which may be adjusted to provide different degreesof grinding pressure.

It is a further object of the invention to provide an improvedsuspension for a swing grinder which is inexpensive and rugged inconstruction and which can be easily incorporated into the structure ofpresently existing swing grinders.

These and other objects will become more apparent after referring to thefollowing specification and attached drawings, in which:

Figure 1 is a side elevational View of a swing grinder constructedaccording to the invention showing the grinder in suspendednon-operating position; and

Figure 2 is a view similar to Figure 1 to a slightly enlarged scaleshowing the grinder in operating position.

Referring more particularly to the drawings reference numeral 2designates generally a swing grinder having the suspension of theinvention incorporated therein. Swing grinder 2 includes a frame 4having an electric drive motor 6 mounted adjacent one end and a grindwheel 8 journaled at its other end. The wheel 8 is driven by means of atransmission V-belt 12 which connects the motor and grinding wheel inthe conventional manner. A handle 14 is provided on the wheel end offrame 4 whereby a workman can manipulate the grinder. A bracket 16 ispivotally mounted on a bar member 18 of frame 4 for suspending thegrinder from an overhanging support.

The structure just described is conventional and is not claimed as myinvention the details of which shall now be described.

The suspension of my invention includes a generally L shape fulcrum arm20 which is mounted on the bracket 16 with its long leg 22 projectingtoward the motor 6 generally parallel with the frame 4. The short leg 24of arm 20 extends toward the frame 4 and is adapted to en- 2,873,558Patented Feb. 17, 1959 gage the bar member 18 when the grinder issuspended in inoperative position to maintain the grinder substantiallybalanced in a horizontal plane, as best shown in Figure l.

A series of holes 26 is provided along the length of the arm 20. Thegrinder is suspended by means of a hoist 28 and chain fall 30. The hoisthook 32 is connected with a bracket 34 which is pivotally mounted in thehole 26 adjacent the bracket 16. The hook 36 of the chain fall isattached to a bracket 38 which is removably fitted in one of the otherholes 26.

The hoist 28 and chain fall 38 may be suspended from trolleys 40 and4.2, respectively, which are mounted for movement along an overheadtrack 44.

The grinder assembly can be raised and lowered from a balanced positionby means of the hoist 28.

In operation, the swing grinder is raised or lowered by means of thehoist 28 to approximate working level just above a workpiece W to beground. Then the hoist is slackened off until the entire assembly issuspended only by the chain fall. This causes the wheel end of thegrinder to tilt downwardly and the grinding wheel 8 to engage theworkpiece W, as shown in Figure 2. The weight of the downwardly tiltedend of the grinder pro vides grinding pressure so that it is notnecessary for the operator to exert downward force on the grinder toobtain grinding pressure as was done heretofore. Thus, the Weight of thegrinder is utilized to obtain grinding pressure and the operator usesthe handle M merely to guide the grinding wheel across the surface ofthe workpiece during the grinding operation. If a maximum degree ofgrinding pressure is desired the chain fall bracket 38 is positioned inthe hole 26 at the extreme end of the arm 20. When lesser amounts ofgrinding pressure are desired the bracket 38 is positioned in one of theholes 26 closer to the center of gravity of the grinder assembly.

Through the use of the suspension of the invention grinding pressures upto five times those heretofore possible have been obtained.

While one embodiment of my invention has been shown and described, itwill be apparent that other adaptations and modifications may be madewithout departing from the scope of the following claim.

I claim:

In a swing grinder adapted to be hung by a first and second suspensionmeans from an overhanging support, said grinder having an elongatedframe, a motor carried by said frame adjacent one end thereof, agrinding wheel rotatably journaled on said frame adjacent the end thereof remote from said motor, and a suspension bracket pivotally mounted onsaid frame adjacent the center of gravity thereof the improvementtherewith of a substantially L-shape fulcrum arm attached to saidbracket, the long leg of said L-shape fulcrum arm extendingsubstantially parallel with said frame toward said motor, the short legof said L-shape fulcrum arm extending substantially normal to said longleg on the side of said bracket toward said grinding wheel, said shortleg normally engaging said frame, said long leg of said fulcrum armhaving a plurality of attaching means along the length thereof forselectively receiving said first suspension means substantially at thecenter of gravity of said frame and said second suspension means at aselected position between said center of gravity and motor end of saidframe.

References Cited in the file of this patent UNITED STATES FATENTS2,132,640 Mummert Oct. 11, 1938 2,718,732 Comstock Sept. 27, 1955FOREIGN PATENTS 437,550 France Feb. 22, 1912

